undefined is not an object (evaluating 'navigator.userAgent')

reportJSException >>>> exception function:createInstanceContext, exception:white screen cause create instanceContext failed,check js stack ->Exception: TypeError: undefined is not an object (evaluating 'navigator.userAgent')

刚开始是因为echarst的js 出现这个错误
但是给 删除之后 还是出现这个问题 踏破铁鞋五米处